Magnetoresistance refers to property of a material to change its resistivity in the presence of a magnetic field. Magnetic sensors can utilize magnetoresistance to sense various components of magnetic fields. For example, magnetic sensor units can be arranged to sense a component of a magnetic fields in specific directions.
For example, U.S. Pat. No. 7,126,330 describes a three-dimensional magnetic sensing device configured to sense three mutually orthogonal components of a magnetic field using three separate sensor units, including first and second magnetic sensor units formed on a common plane on a single substrate to sense x- and y-axis components and a third magnetic sensor formed on a sloped surface with respect to the common plane to sense a z-axis component.